A game is something of little importance (9)
I believe the answer is:
bagatelle
I believe this is a double definition.
'a game' is the first definition.
(bagatelle is a kind of game)
'something of little importance' is the second definition.
'is' is the link.
(Other definitions for bagatelle that I've seen before include "drop in the ocean!" , "Game; piece of music" , "Something trifling and negligible" , "Trivial matter" , "musical composition" .)